Add MOC auto-generation service with sequential numbering

app/services/moc_generator.py

@@ -0,0 +1,90 @@
+"""MOC Number Generation Service for LEGO Instructions Manager"""
+
+from app.models.set import Set
+from app import db
+
+
+class MOCNumberGenerator:
+    """Service for auto-generating MOC (My Own Creation) set numbers"""
+    
+    DEFAULT_PREFIX = 'MOC'
+    DEFAULT_START = 10000
+    
+    @staticmethod
+    def generate_next_number(prefix=None, user_id=None):
+        """
+        Generate the next available MOC number
+        
+        Args:
+            prefix: MOC prefix (default: 'MOC')
+            user_id: Optional user ID to scope MOC numbers per user
+            
+        Returns:
+            str: Next MOC number (e.g., 'MOC-10001')
+        """
+        if prefix is None:
+            prefix = MOCNumberGenerator.DEFAULT_PREFIX
+            
+        # Build query for highest MOC number
+        query = Set.query.filter(
+            Set.is_moc == True,
+            Set.set_number.like(f'{prefix}%')
+        )
+        
+        # Optionally scope to user
+        if user_id:
+            query = query.filter_by(user_id=user_id)
+            
+        # Get highest MOC number
+        highest_moc = query.order_by(Set.set_number.desc()).first()
+        
+        if highest_moc:
+            try:
+                # Extract number from format like "MOC-12345" or "MOC12345"
+                number_part = highest_moc.set_number.replace(prefix, '').replace('-', '').strip()
+                current_num = int(number_part)
+                next_num = current_num + 1
+            except (ValueError, AttributeError):
+                # If parsing fails, start from default
+                next_num = MOCNumberGenerator.DEFAULT_START
+        else:
+            next_num = MOCNumberGenerator.DEFAULT_START
+            
+        return f'{prefix}-{next_num}'
+    
+    @staticmethod
+    def validate_moc_number(set_number, user_id=None):
+        """
+        Check if a MOC number is available
+        
+        Args:
+            set_number: MOC number to validate
+            user_id: Optional user ID to check user-specific availability
+            
+        Returns:
+            bool: True if available, False if already in use
+        """
+        query = Set.query.filter_by(set_number=set_number)
+        
+        if user_id:
+            query = query.filter_by(user_id=user_id)
+            
+        existing = query.first()
+        return existing is None
+    
+    @staticmethod
+    def is_moc_number(set_number, prefix=None):
+        """
+        Check if a set number follows MOC format
+        
+        Args:
+            set_number: Set number to check
+            prefix: MOC prefix to match (default: 'MOC')
+            
+        Returns:
+            bool: True if it's a MOC number
+        """
+        if prefix is None:
+            prefix = MOCNumberGenerator.DEFAULT_PREFIX
+            
+        return set_number.upper().startswith(prefix)